THE QUEEN, 87 today, began her birthday celebrations at the races yesterday, as new figures show just how much she deserves her day of fun after working so hard.

Judging by her huge smile, she was delighted to be spending an afternoon at Newbury Racecourse in Berkshire.

Her Majesty has carried out an estimated 30,000 public engagements, almost 500 a year, since her accession to the throne, according to a devoted chronicler of the royal schedule.

Among the jockeys riding for the Queen yesterday was Hayley Turner on Border Legend but sadly none of her five horses romped home first.

Buckingham Place said that the Queen and Duke of Edinburgh would be spending her birthday in private at Windsor Castle.

The King’s Troop Royal Horse Artillery will fire a 41-gun royal salute from Green Park in London at midday tomorrow to mark the occasion.

Royal enthusiast Tim O’Donovan, 81, has charted the Queen’s diary for decades through the Court Circular published in several UK newspapers.

The retired insurance broker from near Windsor, Berkshire, has used his clippings to calculate the number of individual engagements during her 60-year reign to mark her 87th birthday.

Royal jockey Hayley Turner yesterday

Here is a woman working well into her ninth decade, on a schedule that would prove punishing to most people half her age

Royla enthusiast Tim O'Donovan

According to Mr O’Donovan, the Queen performed 14,429 engagements from 1984, when Buckingham Palace began including her international as well as domestic schedule, to 2012. This works out at an average of 497 a year, or an estimated 30,317 engagements between 1952 and 2012 inclusive.

Mr O’Donovan, who began archiving the Court Circular in 1979, was set the task of totting up Her Majesty’s output by events search engine Daybees.